Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Copyright (C) 2012-2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18#include <clocksource/arm_arch_timer.h>
19#include <linux/compiler.h>
20#include <linux/kvm_host.h>
21
22#include <asm/kvm_hyp.h>
23
24/* vcpu is already in the HYP VA space */
25void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
26{
27 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
28 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
29 u64 val;
30
31 if (timer->enabled) {
32 vtimer->cnt_ctl = read_sysreg_el0(cntv_ctl);
33 vtimer->cnt_cval = read_sysreg_el0(cntv_cval);
34 }
35
36 /* Disable the virtual timer */
37 write_sysreg_el0(0, cntv_ctl);
38
39 /*
40 * We don't need to do this for VHE since the host kernel runs in EL2
41 * with HCR_EL2.TGE ==1, which makes those bits have no impact.
42 */
43 if (!has_vhe()) {
44 /* Allow physical timer/counter access for the host */
45 val = read_sysreg(cnthctl_el2);
46 val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
47 write_sysreg(val, cnthctl_el2);
48 }
49
50 /* Clear cntvoff for the host */
51 write_sysreg(0, cntvoff_el2);
52}
53
54void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
55{
56 struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
57 struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
58 u64 val;
59
60 /* Those bits are already configured at boot on VHE-system */
61 if (!has_vhe()) {
62 /*
63 * Disallow physical timer access for the guest
64 * Physical counter access is allowed
65 */
66 val = read_sysreg(cnthctl_el2);
67 val &= ~CNTHCTL_EL1PCEN;
68 val |= CNTHCTL_EL1PCTEN;
69 write_sysreg(val, cnthctl_el2);
70 }
71
72 if (timer->enabled) {
73 write_sysreg(vtimer->cntvoff, cntvoff_el2);
74 write_sysreg_el0(vtimer->cnt_cval, cntv_cval);
75 isb();
76 write_sysreg_el0(vtimer->cnt_ctl, cntv_ctl);
77 }
78}